Visualisation of xylem sap flow direction in isolated fine lateral roots and estimation of the xylem sap osmotic potential
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- 作者：M. Fritz (1)
R. Ehwald (1) rudolf.ehwald@rz.hu-berlin.de - 关键词：Additional key words hydraulic conductivity – ; maize – ; radial water transport – ; root reflection coefficient – ; xylem loading – ; Zea mays
- 刊名：Biologia Plantarum
- 出版年：2012
- 出版时间：December 2012
- 年：2012
- 卷：56
- 期：4
- 页码：749-756
- 全文大小：657.9 KB
- 参考文献：1. Anderson, W.P., Collins, J.C.: The exudation from excised maize roots bathed in sulphate media. — J. exp. Bot. 20: 72–80, 1969.
2. Anderson, W.P., Aikman, D.P., Meiri, A.: Excised root exudation — a standing-gradient osmotic flow. — Proc. roy. Soc. London, Ser. B — Biol. Sci. 174: 445–458, 1970.
3. Arisz, W.H., Helder, R.J., Van Nie, R.: Analysis of the exudation process in tomato plants. — J. exp. Bot. 2: 257–297, 1951.
4. Bowling, D.J.F., Watson, B.T., Ehwald, R.: The effect of phloem ringing on root-growth and potassium uptake by Helianthus-annuus. — J. exp. Bot. 36: 290–297, 1985.
5. Carpita, N., Sabularse, D., Montezinos, D., Delmer, D.P.: Determination of the pore size of cell walls of living plant cells. — Science 205: 1144–1147, 1979.
6. Eaton, F.M.: The osmotic and vitalistic interpretations of exudation. — Amer. J. Bot. 30: 663–674, 1943.
7. Ehwald, R., P枚rs, Y.: [System for hydroculture of plants without introduction of air. Germany.] — Patent Application DE 102007 040740A1, 2009. [In German]
8. Fritz, M., Lorenzen, S., Popova, M., Ehwald, R.: Transient and permanent changes of xylem sap exudation by root systems of Zea mays after application of hydrostatic and osmotic forces. — Funct. Plant Biol. 37: 813–827, 2010.
9. Fritz, M., Ehwald, R.: Mannitol permeation and radial flow of water in maize roots. — New Phytol. 189: 210–217, 2011.
10. G枚ring, H., Gerlach, I.: Growth rate of plant tissues isolated for a short period with regard to its dependence on quality and quantity of carbon sources. — Z. Pflanzenphysiol. 55: 429–435, 1966.
11. House, C.R., Findlay, N.: Mechanism of fluid exudation from isolated maize roots. — Nature 211: 649–650, 1966a.
12. House, C.R., Findlay, N.: Analysis of transient changes in fluid exudation from isolated maize roots. — J. exp. Bot. 17: 627–640, 1966b.
13. Kramer, J.P., Boyer, S.J.: Water relations of plants and soils. — Academic Press, San Diego — New York — Boston — London — Sydney — Tokyo — Toronto 1995.
14. Klepper, B.: Effects of osmotic pressure on exudation from corn roots. — Aust. J. biol. Sci. 20: 723–735, 1967.
15. Knipfer, T., Fricke, W.: Root pressure and a solute reflection coefficient close to unity exclude a purely apoplastic pathway of radial water transport in barley (Hordeum vulgare). — New Phytol. 187: 159–170, 2010.
16. Lawlor, D.W.: Absorption of polyethylene glycols by plants and their effects on plant growth. — New Phytol. 69: 501–513, 1970.
17. Lenochov谩, Z., Soukup, A., Votrubov谩, O.: Aerenchyma formation in maize roots. — Biol. Plant. 53: 263–270, 2009.
18. Michael, W., Schultz, A., Meshcheryakov, A.B., Ehwald, R.: Apoplasmic and protoplasmic water transport through the parenchyma of the potato storage organ. — Plant Physiol. 115: 1089–1099, 1997.
19. Michael, W., Cholodova, V.P., Ehwald, R.: Gas and liquids in intercellular spaces of maize roots. — Ann. Bot. 84: 665–673, 1999.
20. Munns, R.: Na+, K+ and Cl− in xylem sap flowing to shoots of NaCl-treated barley. — J. exp. Bot. 36: 1032–1042, 1985.
21. Ochiai, K., Matoh, T.: Characterization of the Na+ delivery from roots to shoots in rice under saline stress: excessive salt enhances apoplastic transport in rice plants. — Soil Sci. Plant Nutr. 48: 371–378, 2002.
22. Perry, M.W., Greenway, H.: Permeation of uncharged organicmolecules and water through tomato roots. — Ann. Bot. 37: 225–232, 1973.
23. Sabinin, D.A.: On the root system as an osmotic apparatus. — Bull. Inst. Rech. Biol. Univ. Perm. 5:Supplement 2, 1–136, 1925.
24. Steudle, E.: Water flow in plants and its coupling to other processes: An overview. — In: Fleischer, S. Fleischer B. (ed.): Methods of Enzymology. Vol. 174. Biomembranes. Pp. 183–225. Academic Press, San Diego — New York — Boston — London — Sydney — Tokyo — Toronto 1989.
25. Steudle, E.: Water uptake by plant roots: an integration of views. — Plant Soil 226: 45–56, 2000.
26. Steudle, E., Peterson, C.A.: How does water get through roots? — J. exp. Bot. 49: 775–788, 1998.
27. Tsuchiya, M., Miyake, M., Naito, H.: Physiological-response to salinity in rice plant. III. A possible mechanism for Na+ exclusion in rice root under NaCl-stress conditions. — Jap. J. Crop Sci. 63: 326–332, 1994.
28. Van Andel, O.M.: The influence of salts on the exudation of tomato plants. — Acta. bot. neerl. 2: 445–521, 1953.
29. Zhu, G.-L., Wang, X.-C., Lou, C.-H.: The micro drop recorder; a high resolution monitor of the bleeding rate of plant root systems. — J. exp. Bot. 37: 676–684, 1986. - 作者单位：1. AG Zellbiologie, Humboldt Universit盲t zu Berlin, Invalidenstr. 42, 10115 Berlin, Germany
- 刊物类别：Biomedical and Life Sciences
- 刊物主题：Life Sciences
Plant Sciences - 出版者：Springer Netherlands
- ISSN：1573-8264
文摘
Xylem sap outflow from fine lateral roots (FLRs) isolated from hydroponically grown young maize (Zea mays L.) plants was visualized by local brightening of test solutions contrasted with purified Indian ink particles. Flow into the vessels was indicated by the adsorption of Evans Blue in their walls. The fraction of the FLRs able to exude xylem sap in a mineral medium with 30 mM mannitol decreased with increasing incubation time. This change was strongly retarded, when the FLRs were incubated in a medium containing glucose instead of mannitol. There was a broad range of variation of the osmotic potential of the test solutions (Ψso), wherein the fraction of the FLRs showing an initially reversed flow of the xylem sap varied between zero and unity. A median (M) of the osmotic potential of the xylem sap in FLRs (Ψsx) was estimated. It represents the value of Ψso that was lower than Ψsx in half of the roots of a sample before their transfer to the test solutions (Ψsxo). M was dependent on the osmotic potential of the medium used for growth or pre-incubation of the FLRs. Its value was not dependent on the molecular size of the osmolytes used to adjust Ψso, including dextran 8, which is excluded from cell walls. In all of the studied plants, M was lower than the osmotic potential of the xylem sap collected from the root before isolation of the FLRs. To explain this finding it is assumed that FLRs with Ψsxo > M had a higher hydraulic conductivity and a larger volume contributed to the exuded sap than those with Ψsx < M.